Apache Spark - -

/ @laclefyoshi / ysaeki@r.recruit.co.jp

• • Apache Spark

• • •

•

2

• 2011/04

• 2015/09

• • Druid (KDP, 2015)

• RDB NoSQL ( , 2016; : HBase )

• ESP8266 Wi-Fi IoT (KDP, 2016)

• • (WebDB Forum 2014)

• Spark Streaming (Spark Meetup December 2015)

• Kafka AWS Kinesis (Apache Kafka Meetup Japan #1; 2016)

• (FutureOfData; 2016)

• Queryable State for Kafka Streams (Apache Kafka Meetup Japan #2; 2016)

3

Why Spark?

In-memory Computing

Disk-based Computing In-memory Computing

http://www.jcmit.com/memoryprice.htm6

In-memory Computing

Memcached Hazelcast HANA Exadata

Apache IgniteApache Spark

2003 ~ 2008 ~ 2009 ~ 2011 ~2010 ~

Apache Spark

Lost executor X on xxxx: remote Akka client disassociated

Container marked as failed: container_xxxx on host: xxxx. Exit status: 1

Container killed by YARN for exceeding memory limits

shutting down JVM since 'akka.jvm-exit-on-fatal-error' is enabled for ActorSystem[Remote]

How come?

Apache Spark

Executor Executor

Executor

Driver

Apache Spark

Executor Executor

Executor

Driver

Apache Spark

Disk Memory

$ spark-submit \ --MEMORY_OPTIONS1 \ --MEMORY_OPTIONS2 \ --MEMORY_OPTIONS3 \ --conf ADDITIONAL_OPTIONS1 \ --conf ADDITIONAL_OPTIONS2 \ --class jp.co.recruit.app.Main \ spark-project-1.0-SNAPSHOT.jar

Apache Spark

Apache Spark : Heap

On-heap

--executor-memory XXG or --conf spark.executor.memory=XXG

--conf spark.memory.offHeap.size=XXX

Disk Off-heap

Apache Spark : Executor

Disk

On-heap Off-heap

On-heap Off-heap

Executor

Executor

OS Other Apps

Apache Spark : Container

Disk

On-heap Off-heap

On-heap Off-heap

Executor

Executor

OS Other Apps

Mesos / YARN Container

Overhead

Apache Spark : Overhead

On-heap

--executor-memory XXG or --conf spark.executor.memory=XXG

Disk Off-heap Overhead

--conf spark.mesos.executor.memoryOverhead --conf spark.yarn.executor.memoryOverhead =max(XXG/10 or 384MB)

Apache Spark : Overhead

On-heapDisk Off-heap Overhead

• • Java VM

Apache Spark : Overhead

Disk Off-heapOn-heap

Apache Spark : Garbage Collection

Disk Off-heapOn-heap

Apache Spark : Tachyon

Tachyon

Block Store

Disk Off-heapOn-heap

Apache Spark : Tachyon

Tachyon

Block Store

Disk Off-heapOn-heap

Apache Spark : Project Tungsten

Project Tungsten

Disk Off-heapOn-heap

Apache Spark :

Off-heap300MBDisk On-heap

Don’t touch!

Apache Spark : User Memory

Off-heap300MBDisk

--conf spark.memory.fraction=0.6

Memory Fraction User Memory

• • • Memory Fraction

Apache Spark : Execution Storage

Off-heap300MBDisk User Memory

--conf spark.memory.storageFraction=0.5

Storage Fraction

Execution Fraction

Apache Spark : Execution Storage

Off-heap300MBDisk User Memory

Storage Fraction

Execution Fraction

• • Broadcast Accumulator

• Shuffle Join Sort Aggregate

•

Apache Spark : Unified Memory

Off-heap300MBDisk User Memory

Storage Fraction

Execution Fraction

Examples

User Memory

Off-heap300MBDisk User Memory

Storage Fraction

Execution Fraction

or

User Memory

Off-heap300MBDisk User Memory

Storage Fraction

Execution Fraction

Storage Fraction

Off-heap300MBDisk User Memory

Storage Fraction

Execution Fraction

or

Storage Fraction

Off-heap300MBDisk User Memory

Storage Fraction

Execution Fraction

Off-heap300MBDisk User Memory

Storage Fraction

Execution Fraction

or

Off-heap300MBDisk User Memory

Storage Fraction

Execution Fraction

OutOfMemoryError

How Spark can help us not to stop our applications

Apache Spark

Disk User Memory

Storage Fraction

Execution Fraction

SpillProject Tungsten

Project Tungsten

Off-heap300MB

Spill

Apache Spark : Garbage Collection

Disk Off-heapOn-heap

JVM : Garbage Collection

-XX:+UseConcMarkSweepGC // GC

-XX:+UseParNewGC // GC

-XX:+CMSParallelRemarkEnabled // GC Remark

-XX:+DisableExplicitGC // GC(System.gc())

JVM : Garbage Collection

-XX:+HeapDumpOnOutOfMemoryError // OoME

-XX:+PrintGCDetails // GC

-XX:+PrintGCDateStamps //

-XX:+UseGCLogFileRotation // GC

JVM

$ spark-submit \ --executor-memory 8GB \ --num-executors 20 \ --executor-cores 2 \ --conf \ "spark.executor.extraJavaOptions=..." \ --spark.memory.offHeap.enabled=true \ --spark.memory.offHeap.size=1073741824 \ --class jp.co.recruit.app.Main \ spark-project-1.0-SNAPSHOT.jar

!

How we can help ourselves not to stop our applications

RDD

Off-heap300MBDisk User Memory

Storage Fraction

Execution Fraction

rdd.cache() rdd.persist() rdd.persist(StorageLevel.MEMORY_ONLY)

RDD

Off-heap300MBDisk User Memory

Storage Fraction

Execution Fraction

MEMORY_ONLY MEMORY_ONLY_2 MEMORY_ONLY_SER

MEMORY_AND_DISK MEMORY_AND_DISK_2 MEMORY_AND_DISK_SER

DISK_ONLY

OFF_HEAP

RDD

Off-heap300MBDisk User Memory

Storage Fraction

Execution Fraction

+

RDD 1

• SizeEstimator

$ spark-shell > import org.apache.spark.util.SizeEstimator

> SizeEstimator.estimate("1234") res0: Long = 48

> val rdd = sc.makeRDD( (1 to 100000).map(e => e.toString).toSeq)

> SizeEstimator.estimate(rdd) res2: Long = 7246792

RDD 2

• Web UI Storage panel

> SizeEstimator.estimate(rdd) res2: Long = 7246792

> rdd.persist(StorageLevel.MEMORY_ONLY)

RDD

> orders = sc.textFile("lineorder.csv") orders: org.apache.spark.rdd.RDD[String] = ... > result = orders.map(...) result: org.apache.spark.rdd.RDD[String] = ...

> orders.persist(StorageLevel.MEMORY_ONLY) > result.persist(StorageLevel.MEMORY_AND_DISK)

RDD

> result.persist(StorageLevel.MEMORY_AND_DISK)

RDD

> orders.persist(StorageLevel.MEMORY_ONLY)

16/12/09 14:34:06 WARN MemoryStore: Not enough space to cache rdd_1_39 in memory! (computed 44.4 MB so far)

16/12/09 14:34:06 WARN BlockManager: Block rdd_1_39 could not be removed as it was not found on disk or in memory

16/12/09 14:34:06 WARN BlockManager: Putting block rdd_1_39 failed

•

Off-heap300MBDisk User Memory

Storage Fraction

Execution Fraction

•

Off-heap300MBDisk User Memory

Storage Fraction

Execution Fraction

• RDD

> orders.partitions.size res3: Int = 40 > orders.repartition(80)

> orders.persist(StorageLevel.MEMORY_ONLY)

Off-heap300MBDisk User Memory

Storage Fraction

Execution Fraction

OutOfMemoryError

RDD

Off-heap300MBDisk User Memory

Storage Fraction

Execution Fraction

> rdd.unpersist(true) //

> rdd.unpersist(false) //

Execution Fraction

•

• • • Garbage Collection

• GC

• Shuffle

Apache Spark

Off-heap300MBUser Memory

--conf spark.memory.storageFraction

Storage Fraction

Execution Fraction

--conf spark.memory.fraction --conf spark.memory.offHeap.size

--executor-memory --conf spark.executor.memory

Overhead

--conf spark.mesos. executor.memoryOverhead --conf spark.yarn. executor.memoryOverhead

: Executor

• [A] Storage Fraction = RDD

• [B] Execution Fraction = A

• [C] On-heap = (A + B) / 0.6 + 300MB // 0.6 User Memory

• [D] Off-heap = RDD

• [E] Overhead = max(C * 0.1, 384MB) //

• [F] 1 Container (Executor)

• [G] OS

• [H]

(C + D + E) * F + G < H

: Driver ?

Driver Memory Overhead

--conf spark.mesos. driver.memoryOverhead --conf spark.yarn. driver.memoryOverhead

--driver-memory --conf spark.driver.memory

--conf spark.driver.maxResultSize=1G

Action (collect, reduce, take ) !

Driver

Yes, It’s all about Spark Memory.

Enjoy In-memory Computing!